The present invention relates generally to intramedullary nails, and more particularly to a new and improved intramedullary nail system. The system primarily includes an intramedullary nail wherein the proximal portion thereof includes a cavity perpendicular to the longitudinal axis of the nail and an elongated throughbore that is parallel to the longitudinal axis of the nail. A modular sleeve, having a multiplicity of hole patterns formed therein, is received onto the proximal portion of the intramedullary nail. At the distal end of the proximal portion of the intramedullary nail, a fastening assembly is employed to secure the modular sleeve to the proximal portion of the intramedullary nail such that instrumentation may freely pass through the entire length of the elongated throughbore. The fully assembled intramedullary nail system is then able to be secured to the bone tissue with fastener elements capable of being inserted at a variety of different angles through the modular sleeve and the perpendicular cavity.
Intramedullary nails are typically used to treat fractures of various long bones, such as diaphyseal fractures of the femur, tibia, and humerus bones. Typically, intramedullary nails are substantially elongated metallic members having one or more cylindrical cavities (typically located in proximal and distal locations) which are perpendicular to the longitudinal axis of the intramedullary nail for receiving a fastener element, such as a transcortical screw. The reason for the presence of the cylindrical cavities is rather simple. Because the intramedullary nails are formed of extremely durable metallic material, e.g., stainless steel, titanium, etc., it is generally undesirable to attempt to drill through this material for obvious reasons. Accordingly, during the manufacturing process of the intramedullary nails, these cylindrical cavities are formed in one or more positions along the length of the intramedullary nails.
The intramedullary nails are positioned within the medullary cavity and can be secured to the proximal and distal fracture segments using transcortical screws which penetrate both cortices of the bone, as well as pass through the cylindrical cavities formed in the intramedullary nail. Thus, unlike Steinmann pins, which can only counteract bending forces, interlocked intramedullary nails can also counteract axial and rotational forces. The interlocked intramedullary nails have a mechanical advantage in comparison to bone plates because the intramedullary nails are implanted centrally within the intramedullary cavity (i.e., the mechanical axis of long bones) rather than placed eccentrically on the surface of the bone.
One problem which has been recognized is that the perpendicular orientation of the cylindrical cavities, relative to the longitudinal axis of the intramedullary nail, severely limits the surgeon""s options as to how he or she can fasten the intramedullary nail to the bone tissue with the transcortical screws. Although the perpendicular orientation of the cylindrical cavities is usually acceptable, it is sometimes necessary, due to the site of the fracture, the severity thereof, or the presence of nearby blood vessels and nerves, to place the transcortical screws through the cylindrical cavities in a non-perpendicular orientation relative to the longitudinal axis of the intramedullary nail.
One approach to overcoming this problem can be found in U.S. Pat. No. 5,653,709 to Frigg which discloses a marrow (i.e., intramedullary) nail which includes a nail having a distal end, a proximal end, a longitudinal axis, and a slot in the area of the proximal end, running transverse to the longitudinal axis. A cylindrical casing is provided, which can be slid onto the proximal end of the marrow nail. This casing exhibits a cylindrical axis as well as at least two openings placed at opposite ends of the cylindrical cover. The casing is formed in such a way that upon being slid onto marrow nail, it can be brought into an axial fastening position relative to the nail. Openings are thereby positioned in the fastening position of the casing in the area of the slot and with the latter, the marrow nail and the casing form a transverse channel to admit bone fixation devices.
Although the system disclosed in U.S. Pat. No. 5,653,709 to Frigg appears to provide a means for altering the angles available for the bone fixation devices, e.g., transcortical screws, to be inserted through the slot in the intramedullary nail, it does, however, suffer from a significant deficiency.
Recently, there has been a growing trend towards the use of intramedullary nails which have an elongated throughbore extending centrally along the longitudinal axis of the intramedullary nail so as to permit instrumentation to be inserted into the elongated throughbore, e.g., driver devices for inserting the intramedullary nail into the reamed intramedullary canal.
Because an elongated throughbore is not at all contemplated and solid fixation devices are used, it would be impossible to insert any instrumentation, such as a driver or other devices, inside the center of the intramedullary nail that could extend to, and beyond, the distal end thereof, in the device disclosed in U.S. Pat. No. 5,653,709 to Frigg.
Therefore, there still exists a need for a device for the proximal portion of an intramedullary nail which permits fastener elements, such as transcortical screws, to be inserted through a slot formed in the intramedullary nail at a variety of different angles and orientations relative to the longitudinal axis of the intramedullary nail, while simultaneously permitting instrumentation to be fully and completely received into an elongated throughbore formed along the longitudinal axis of the intramedullary nail even after the device has been secured to the proximal portion of the intramedullary nail.
In accordance with a first embodiment of the present invention, a fracture fixation system is provided, comprising: (1) an intramedullary nail member having a first area defining a throughbore, wherein the throughbore of the intramedullary nail member is oriented substantially parallel relative to the longitudinal axis of the intramedullary nail member; (2) a sleeve member adapted to be received over the intramedullary nail member, wherein the sleeve member has a first area defining a throughbore, wherein the throughbore of the sleeve member is oriented substantially parallel relative to the longitudinal axis of the sleeve member; and (3) a securing mechanism for securing the sleeve member to the intramedullary nail member such that the throughbore of the intramedullary nail member proximal to the securing mechanism is substantially unobstructed.
In accordance with a second embodiment of the present invention, a fracture fixation system is provided, comprising: (1) an intramedullary nail member including a first area defining a throughbore, wherein the throughbore of the intramedullary nail member is oriented substantially parallel relative to the longitudinal axis of the intramedullary nail member, wherein the intramedullary nail member includes a second area defining an opening which extends completely through at least a portion of the throughbore of the intramedullary nail; (2) a sleeve member adapted to be received over the intramedullary nail member, wherein the sleeve member includes a first area defining a throughbore, wherein the throughbore of the sleeve member is oriented substantially parallel relative to the longitudinal axis of the sleeve member, wherein the sleeve member includes a second area defining an opening which extends completely through at least a portion of the throughbore of the sleeve member; (3) an insert member including an area defining a throughbore, wherein the insert member is capable of being received in the opening of the intramedullary nail member and the opening of the sleeve member so as to substantially align the throughbore of the intramedullary nail member and the throughbore of the insert member; and (4) a fastening member for fastening the intramedullary nail member to the insert member so as to secure the sleeve member to the intramedullary nail member such that the throughbore of the intramedullary nail member is substantially unobstructed.
In accordance with a third embodiment of the present invention, a fracture fixation system is provided, comprising: (1) a substantially cylindrical intramedullary nail member including a first area defining a throughbore, wherein the throughbore of the intramedullary nail member is oriented substantially parallel relative to the longitudinal axis of the intramedullary nail member, wherein the intramedullary nail member includes a second area defining an opening which extends completely through at least a portion of the throughbore of the intramedullary nail, wherein the intramedullary nail member includes a third area defining a second opening which extends completely through at least a portion of the throughbore for receiving a transcortical screw; (2) a substantially cylindrical sleeve member adapted to be received over the intramedullary nail member, wherein the sleeve member includes a first area defining a throughbore, wherein the throughbore of the sleeve member is oriented substantially parallel relative to the longitudinal axis of the sleeve member, wherein the sleeve member includes a second area defining an opening which extends completely through at least a portion of the throughbore of the sleeve member, wherein the sleeve member includes a third area defining a second opening which extends completely through at least a portion of the throughbore for receiving a transcortical screw; (3) an insert member including an area defining a throughbore, wherein the insert member is capable of being received in the opening of the intramedullary nail member and the opening of the sleeve member so as to substantially align the throughbore of the intramedullary nail member and the throughbore of the insert member; and (4) a fastening member for fastening the intramedullary nail member to the insert member so as to secure the sleeve member to the intramedullary nail member such that the throughbore of the intramedullary nail member is substantially unobstructed.
In accordance with a fourth embodiment of the present invention, a method for long bone fracture fixation is provided, comprising: (1) providing a long bone fracture fixation system, including: (a) an intramedullary nail member having a first area defining a throughbore, wherein the throughbore of the intramedullary nail member is oriented substantially parallel relative to the longitudinal axis of the intramedullary nail member; (b) a sleeve member adapted to be received over the intramedullary nail member, wherein the sleeve member has a first area defining a throughbore, wherein the throughbore of the sleeve member is oriented substantially parallel relative to the longitudinal axis of the sleeve member; and (c) a securing mechanism for securing the sleeve member to the intramedullary nail member such that the throughbore of the intramedullary nail member proximal to the securing mechanism is substantially unobstructed; (2) inserting the long bone fracture fixation system into an intramedullary canal; and (3) securing the long bone fracture fixation system in the intramedullary canal with a least one transcortical screw.
In accordance with a fifth embodiment of the present invention, a method for long bone fracture fixation is provided, comprising: (1) providing a long bone fracture fixation system, including: (a) an intramedullary nail member including a first area defining a throughbore, wherein the throughbore of the intramedullary nail member is oriented substantially parallel relative to the longitudinal axis of the intramedullary nail member, wherein the intramedullary nail member includes a second area defining an opening which extends completely through at least a portion of the throughbore of the intramedullary nail; (b) a sleeve member adapted to be received over the intramedullary nail member, wherein the sleeve member includes a first area defining a throughbore, wherein the throughbore of the sleeve member is oriented substantially parallel relative to the longitudinal axis of the sleeve member, wherein the sleeve member includes a second area defining an opening which extends completely through at least a portion of the throughbore of the sleeve member; (c) an insert member including an area defining a throughbore; and (d) a fastening member for fastening the intramedullary nail member to the insert member so as to secure the sleeve member to the intramedullary nail member such that the throughbore of the intramedullary nail member is substantially unobstructed; (2) inserting the long bone fracture fixation system into an intramedullary canal; and (3) securing the long bone fracture fixation system in the intramedullary canal with a least one transcortical screw.
In accordance with a sixth embodiment of the present invention, a method for long bone fracture fixation is provided, comprising: (1) providing a long bone fracture fixation system, including: (a) a substantially cylindrical intramedullary nail member including a first area defining a throughbore, wherein the throughbore of the intramedullary nail member is oriented substantially parallel relative to the longitudinal axis of the intramedullary nail member, wherein the intramedullary nail member includes a second area defining an opening which extends completely through at least a portion of the throughbore of the intramedullary nail, wherein the intramedullary nail member includes a third area defining a second opening which extends completely through at least a portion of the throughbore for receiving a transcortical screw; (b) a substantially cylindrical sleeve member adapted to be received over the intramedullary nail member, wherein the sleeve member includes a first area defining a throughbore, wherein the throughbore of the sleeve member is oriented substantially parallel relative to the longitudinal axis of the sleeve member, wherein the sleeve member includes a second area defining an opening which extends completely through at least a portion of the throughbore of the sleeve member, wherein the sleeve member includes a third area defining a second opening which extends completely through at least a portion of the throughbore for receiving a transcortical screw; (c) an insert member including an area defining a throughbore, wherein the insert member is capable of being received in the opening of the intramedullary nail member and the opening of the sleeve member so as to substantially align the throughbore of the intramedullary nail member and the throughbore of the insert member; and (d) a fastening member for fastening the intramedullary nail member to the insert member so as to secure the sleeve member to the intramedullary nail member such that the throughbore of the intramedullary nail member is substantially unobstructed; (2) inserting the long bone fracture fixation system into an intramedullary canal; and (3) securing the long bone fracture fixation system in the intramedullary canal with a least one transcortical screw.
A more complete appreciation of the present invention and its scope can be obtained from the following detailed description of the invention and the appended claims.